<?php
class DB
{
    protected $database_type;
    
    protected $server;
    
    protected $username;
    
    protected $password;
    
    protected $database_file;
    
    protected $port;
    
    protected $charset = 'utf8';
    
    protected $database_name;
    
    protected $option = array();
    
    protected $queryString;
    
    public function __construct($options = null)
    {
        try
        {
            $commands = array();
            
            if (is_string($options) && !empty($options))
            {
                if (strtolower($this->database_type) == 'sqlite')
                {
                    $this->database_file = $options;
                }
                else
                {
                    $this->database_name = $options;
                }
            }
            elseif (is_array($options))
            {
                foreach ($options as $option => $value)
                {
                    $this->$option = $value;
                }
            }
            
            if (isset($this->port) && is_int($this->port * 1))
            {
                $port = $this->port;
            }
            
            $set_charset = "SET NAMES '" . $this->charset . "'";
            $type        = strtolower($this->database_type);
            $is_port     = isset($port);
            
            switch ($type)
            {
                case 'mariadb':
                    $type = 'mysql';
                
                case 'mysql':
                    $commands[] = 'SET SQL_MODE=ANSI_QUOTES';
                
                case 'pgsql':
                    $dsn        = $type . ':host=' . $this->server . ($is_port ? ';port=' . $port : '') . ';dbname=' . $this->database_name;
                    $commands[] = $set_charset;
                    break;
                
                case 'sybase':
                    $dsn        = 'dblib:host=' . $this->server . ($is_port ? ':' . $port : '') . ';dbname=' . $this->database_name;
                    $commands[] = $set_charset;
                    break;
                
                case 'oracle':
                    $dsn = 'oci:host=' . $this->server . ($is_port ? ';port=' . $port : '') . ';dbname=' . $this->database_name . ';charset=' . $this->charset;
                    break;
                
                case 'mssql':
                    $dsn = strpos(PHP_OS, 'WIN') !== false ? 'sqlsrv:server=' . $this->server . ($is_port ? ',' . $port : '') . ';database=' . $this->database_name : 'dblib:host=' . $this->server . ($is_port ? ':' . $port : '') . ';dbname=' . $this->database_name;
                    
                    $commands[] = 'SET QUOTED_IDENTIFIER ON';
                    $commands[] = $set_charset;
                    break;
                
                case 'sqlite':
                    $dsn            = $type . ':' . $this->database_file;
                    $this->username = null;
                    $this->password = null;
                    break;
            }
            
            $this->pdo = new PDO($dsn, $this->username, $this->password, $this->option);
            
            foreach ($commands as $value)
            {
                $this->pdo->exec($value);
            }
        }
        catch (PDOException $e)
        {
            throw new Exception($e->getMessage());
        }
    }
    
    public function beginTransaction()
    {
        $this->pdo->setAttribute(PDO::ATTR_AUTOCOMMIT, 0);
        
        $this->pdo->beginTransaction();
    }
    
    public function commit()
    {
        $this->pdo->commit();
    }
    
    public function rollBack()
    {
        $this->pdo->rollBack();
    }
    
    public function checkResult($affected)
    {
        if (intval($affected) > 0)
        {
            
            $this->commit();
            
        }
        else
        {
            
            $this->rollBack();
            
        }
    }
    
    public function endTransaction()
    {
        $this->pdo->setAttribute(PDO::ATTR_AUTOCOMMIT, 1);
    }
    
    public function query($query)
    {
        $this->queryString = $query;
        
        return $this->pdo->query($query);
    }
    
    public function exec($query)
    {
        $this->queryString = $query;
        
        return $this->pdo->exec($query);
    }
    
    public function quote($string)
    {
        return $this->pdo->quote($string);
    }
    
    protected function column_quote($string)
    {
        return '"' . str_replace('.', '"."', preg_replace('/(^#|\(JSON\))/', '', $string)) . '"';
    }
    
    protected function column_push($columns)
    {
        if ($columns == '*')
        {
            return $columns;
        }
        
        if (is_string($columns))
        {
            $columns = array(
                $columns
            );
        }
        
        $stack = array();
        
        foreach ($columns as $key => $value)
        {
            preg_match('/([a-zA-Z0-9_\-\.]*)\s*\(([a-zA-Z0-9_\-]*)\)/i', $value, $match);
            
            if (isset($match[1], $match[2]))
            {
                array_push($stack, $this->column_quote($match[1]) . ' AS ' . $this->column_quote($match[2]));
            }
            else
            {
                array_push($stack, $this->column_quote($value));
            }
        }
        
        return implode($stack, ',');
    }
    
    protected function array_quote($array)
    {
        $temp = array();
        
        foreach ($array as $value)
        {
            $temp[] = is_int($value) ? $value : $this->pdo->quote($value);
        }
        
        return implode($temp, ',');
    }
    
    protected function inner_conjunct($data, $conjunctor, $outer_conjunctor)
    {
        $haystack = array();
        
        foreach ($data as $value)
        {
            $haystack[] = '(' . $this->data_implode($value, $conjunctor) . ')';
        }
        
        return implode($outer_conjunctor . ' ', $haystack);
    }
    
    protected function fn_quote($column, $string)
    {
        return (strpos($column, '#') === 0 && preg_match('/^[A-Z0-9\_]*\([^)]*\)$/', $string)) ? $string : $this->quote($string);
    }
    
    protected function data_implode($data, $conjunctor, $outer_conjunctor = null)
    {
        $wheres = array();
        
        foreach ($data as $key => $value)
        {
            $type = gettype($value);
            
            if (preg_match("/^(AND|OR)\s*#?/i", $key, $relation_match) && $type == 'array')
            {
                $wheres[] = 0 !== count(array_diff_key($value, array_keys(array_keys($value)))) ? '(' . $this->data_implode($value, ' ' . $relation_match[1]) . ')' : '(' . $this->inner_conjunct($value, ' ' . $relation_match[1], $conjunctor) . ')';
            }
            else
            {
                preg_match('/(#?)([\w\.]+)(\[(\>|\>\=|\<|\<\=|\!|\<\>|\>\<)\])?/i', $key, $match);
                $column = $this->column_quote($match[2]);
                
                if (isset($match[4]))
                {
                    if ($match[4] == '')
                    {
                        $wheres[] = $column . ' ' . $match[4] . '= ' . $this->quote($value);
                    }
                    elseif ($match[4] == '!')
                    {
                        switch ($type)
                        {
                            case 'NULL':
                                $wheres[] = $column . ' IS NOT NULL';
                                break;
                            
                            case 'array':
                                $wheres[] = $column . ' NOT IN (' . $this->array_quote($value) . ')';
                                break;
                            
                            case 'integer':
                            case 'double':
                                $wheres[] = $column . ' != ' . $value;
                                break;
                            
                            case 'boolean':
                                $wheres[] = $column . ' != ' . ($value ? '1' : '0');
                                break;
                            
                            case 'string':
                                $wheres[] = $column . ' != ' . $this->fn_quote($key, $value);
                                break;
                        }
                    }
                    else
                    {
                        if ($match[4] == '<>' || $match[4] == '><')
                        {
                            if ($type == 'array')
                            {
                                if ($match[4] == '><')
                                {
                                    $column .= ' NOT';
                                }
                                
                                if (is_numeric($value[0]) && is_numeric($value[1]))
                                {
                                    $wheres[] = '(' . $column . ' BETWEEN ' . $value[0] . ' AND ' . $value[1] . ')';
                                }
                                else
                                {
                                    $wheres[] = '(' . $column . ' BETWEEN ' . $this->quote($value[0]) . ' AND ' . $this->quote($value[1]) . ')';
                                }
                            }
                        }
                        else
                        {
                            if (is_numeric($value))
                            {
                                $wheres[] = $column . ' ' . $match[4] . ' ' . $value;
                            }
                            else
                            {
                                $datetime = strtotime($value);
                                
                                if ($datetime)
                                {
                                    $wheres[] = $column . ' ' . $match[4] . ' ' . $this->quote(date('Y-m-d H:i:s', $datetime));
                                }
                            }
                        }
                    }
                }
                else
                {
                    if (is_int($key))
                    {
                        $wheres[] = $this->quote($value);
                    }
                    else
                    {
                        switch ($type)
                        {
                            case 'NULL':
                                $wheres[] = $column . ' IS NULL';
                                break;
                            
                            case 'array':
                                $wheres[] = $column . ' IN (' . $this->array_quote($value) . ')';
                                break;
                            
                            case 'integer':
                            case 'double':
                                $wheres[] = $column . ' = ' . $value;
                                break;
                            
                            case 'boolean':
                                $wheres[] = $column . ' = ' . ($value ? '1' : '0');
                                break;
                            
                            case 'string':
                                $wheres[] = $column . ' = ' . $this->fn_quote($key, $value);
                                break;
                        }
                    }
                }
            }
        }
        
        return implode($conjunctor . ' ', $wheres);
    }
    
    protected function where_clause($where)
    {
        $where_clause = '';
        
        if (is_array($where))
        {
            $where_keys = array_keys($where);
            $where_AND  = preg_grep("/^AND\s*#?$/i", $where_keys);
            $where_OR   = preg_grep("/^OR\s*#?$/i", $where_keys);
            
            $single_condition = array_diff_key($where, array_flip(explode(' ', 'AND OR GROUP ORDER HAVING LIMIT LIKE MATCH')));
            
            if ($single_condition != array())
            {
                $where_clause = ' WHERE ' . $this->data_implode($single_condition, '');
            }
            
            if (!empty($where_AND))
            {
                $value        = array_values($where_AND);
                $where_clause = ' WHERE ' . $this->data_implode($where[$value[0]], ' AND');
            }
            
            if (!empty($where_OR))
            {
                $value        = array_values($where_OR);
                $where_clause = ' WHERE ' . $this->data_implode($where[$value[0]], ' OR');
            }
            
            if (isset($where['LIKE']))
            {
                $like_query = $where['LIKE'];
                
                if (is_array($like_query))
                {
                    $is_OR       = isset($like_query['OR']);
                    $clause_wrap = array();
                    
                    if ($is_OR || isset($like_query['AND']))
                    {
                        $connector  = $is_OR ? 'OR' : 'AND';
                        $like_query = $is_OR ? $like_query['OR'] : $like_query['AND'];
                    }
                    else
                    {
                        $connector = 'AND';
                    }
                    
                    foreach ($like_query as $column => $keyword)
                    {
                        $keyword = is_array($keyword) ? $keyword : array(
                            $keyword
                        );
                        
                        foreach ($keyword as $key)
                        {
                            preg_match('/(%?)([a-zA-Z0-9_\-\.]*)(%?)((\[!\])?)/', $column, $column_match);
                            
                            if ($column_match[1] == '' && $column_match[3] == '')
                            {
                                $column_match[1] = '%';
                                $column_match[3] = '%';
                            }
                            
                            $clause_wrap[] = $this->column_quote($column_match[2]) . ($column_match[4] != '' ? ' NOT' : '') . ' LIKE ' . $this->quote($column_match[1] . $key . $column_match[3]);
                        }
                    }
                    
                    $where_clause .= ($where_clause != '' ? ' AND ' : ' WHERE ') . '(' . implode($clause_wrap, ' ' . $connector . ' ') . ')';
                }
            }
            
            if (isset($where['MATCH']))
            {
                $match_query = $where['MATCH'];
                
                if (is_array($match_query) && isset($match_query['columns'], $match_query['keyword']))
                {
                    $where_clause .= ($where_clause != '' ? ' AND ' : ' WHERE ') . ' MATCH ("' . str_replace('.', '"."', implode($match_query['columns'], '", "')) . '") AGAINST (' . $this->quote($match_query['keyword']) . ')';
                }
            }
            
            if (isset($where['GROUP']))
            {
                $where_clause .= ' GROUP BY ' . $this->column_quote($where['GROUP']);
            }
            
            if (isset($where['ORDER']))
            {
                $rsort = '/(^[a-zA-Z0-9_\-\.]*)(\s*(DESC|ASC))?/';
                
                if (is_array($where['ORDER']))
                {
                    if (isset($where['ORDER'][1]) && is_array($where['ORDER'][1]))
                    {
                        $where_clause .= ' ORDER BY FIELD(' . $this->column_quote($where['ORDER'][0]) . ', ' . $this->array_quote($where['ORDER'][1]) . ')';
                    }
                    else
                    {
                        $stack = array();
                        
                        foreach ($where['ORDER'] as $column)
                        {
                            preg_match($rsort, $column, $order_match);
                            
                            array_push($stack, '"' . str_replace('.', '"."', $order_match[1]) . '"' . (isset($order_match[3]) ? ' ' . $order_match[3] : ''));
                        }
                        
                        $where_clause .= ' ORDER BY ' . implode($stack, ',');
                    }
                }
                else
                {
                    preg_match($rsort, $where['ORDER'], $order_match);
                    
                    $where_clause .= ' ORDER BY "' . str_replace('.', '"."', $order_match[1]) . '"' . (isset($order_match[3]) ? ' ' . $order_match[3] : '');
                }
                
                if (isset($where['HAVING']))
                {
                    $where_clause .= ' HAVING ' . $this->data_implode($where['HAVING'], '');
                }
            }
            
            if (isset($where['LIMIT']))
            {
                if (is_numeric($where['LIMIT']))
                {
                    $where_clause .= ' LIMIT ' . $where['LIMIT'];
                }
                
                if (is_array($where['LIMIT']) && is_numeric($where['LIMIT'][0]) && is_numeric($where['LIMIT'][1]))
                {
                    $where_clause .= ' LIMIT ' . $where['LIMIT'][0] . ',' . $where['LIMIT'][1];
                }
            }
        }
        else
        {
            if ($where != null)
            {
                $where_clause .= ' ' . $where;
            }
        }
        
        return $where_clause;
    }
    
    protected function select_context($table, $join, &$columns = null, $where = null, $column_fn = null)
    {
        $table    = '"' . $table . '"';
        $join_key = is_array($join) ? array_keys($join) : null;
        
        if (isset($join_key[0]) && strpos($join_key[0], '[') === 0)
        {
            $table_join = array();
            
            $join_array = array(
                '>' => 'LEFT',
                '<' => 'RIGHT',
                '<>' => 'FULL',
                '><' => 'INNER'
            );
            
            foreach ($join as $sub_table => $relation)
            {
                preg_match('/(\[(\<|\>|\>\<|\<\>)\])?([a-zA-Z0-9_\-]*)/', $sub_table, $match);
                
                if ($match[2] != '' && $match[3] != '')
                {
                    if (is_string($relation))
                    {
                        $relation = 'USING ("' . $relation . '")';
                    }
                    
                    if (is_array($relation))
                    {
                        if (isset($relation[0]))
                        {
                            $relation = 'USING ("' . implode($relation, '", "') . '")';
                        }
                        else
                        {
                            $relation = 'ON ' . $table . '."' . key($relation) . '" = "' . $match[3] . '"."' . current($relation) . '"';
                        }
                    }
                    
                    $table_join[] = $join_array[$match[2]] . ' JOIN "' . $match[3] . '" ' . $relation;
                }
            }
            
            $table .= ' ' . implode($table_join, ' ');
        }
        else
        {
            if (is_null($columns))
            {
                if (is_null($where))
                {
                    if (is_array($join) && isset($column_fn))
                    {
                        $where   = $join;
                        $columns = null;
                    }
                    else
                    {
                        $where   = null;
                        $columns = $join;
                    }
                }
                else
                {
                    $where   = $join;
                    $columns = null;
                }
            }
            else
            {
                $where   = $columns;
                $columns = $join;
            }
        }
        
        if (isset($column_fn))
        {
            if ($column_fn == 1)
            {
                $column = '1';
                
                if (is_null($where))
                {
                    $where = $columns;
                }
                else
                {
                    $where = $join;
                }
            }
            else
            {
                if (empty($columns))
                {
                    $columns = '*';
                    $where   = $join;
                }
                
                $column = $column_fn . '(' . $this->column_push($columns) . ')';
            }
        }
        else
        {
            $column = $this->column_push($columns);
        }
        
        return 'SELECT ' . $column . ' FROM ' . $table . $this->where_clause($where);
    }
    
    public function select($table, $join, $columns = null, $where = null)
    {
        $query = $this->query($this->select_context($table, $join, $columns, $where));
        
        return $query ? $query->fetchAll((is_string($columns) && $columns != '*') ? PDO::FETCH_COLUMN : PDO::FETCH_ASSOC) : false;
    }
    
    public function insert($table, $datas)
    {
        $lastId = array();
        
        if (!isset($datas[0]))
        {
            $datas = array(
                $datas
            );
        }
        
        foreach ($datas as $data)
        {
            $keys    = array_keys($data);
            $values  = array();
            $columns = array();
            
            foreach ($data as $key => $value)
            {
                array_push($columns, $this->column_quote($key));
                
                switch (gettype($value))
                {
                    case 'NULL':
                        $values[] = 'NULL';
                        break;
                    
                    case 'array':
                        preg_match("/\(JSON\)\s*([\w]+)/i", $key, $column_match);
                        
                        if (isset($column_match[0]))
                        {
                            $values[] = $this->quote(json_encode($value));
                        }
                        else
                        {
                            $values[] = $this->quote(serialize($value));
                        }
                        break;
                    
                    case 'boolean':
                        $values[] = ($value ? '1' : '0');
                        break;
                    
                    case 'integer':
                    case 'double':
                    case 'string':
                        $values[] = $this->fn_quote($key, $value);
                        break;
                }
            }
            
            $this->exec('INSERT INTO "' . $table . '" (' . implode(', ', $columns) . ') VALUES (' . implode($values, ', ') . ')');
            
            $lastId[] = $this->pdo->lastInsertId();
        }
        
        return count($lastId) > 1 ? $lastId : $lastId[0];
    }
    
    public function update($table, $data, $where = null)
    {
        $fields = array();
        
        foreach ($data as $key => $value)
        {
            preg_match('/([\w]+)(\[(\+|\-|\*|\/)\])?/i', $key, $match);
            
            if (isset($match[3]))
            {
                if (is_numeric($value))
                {
                    $fields[] = $this->column_quote($match[1]) . ' = ' . $this->column_quote($match[1]) . ' ' . $match[3] . ' ' . $value;
                }
            }
            else
            {
                $column = $this->column_quote($key);
                
                switch (gettype($value))
                {
                    case 'NULL':
                        $fields[] = $column . ' = NULL';
                        break;
                    
                    case 'array':
                        preg_match("/\(JSON\)\s*([\w]+)/i", $key, $column_match);
                        
                        if (isset($column_match[0]))
                        {
                            $fields[] = $this->column_quote($column_match[1]) . ' = ' . $this->quote(json_encode($value));
                        }
                        else
                        {
                            $fields[] = $column . ' = ' . $this->quote(serialize($value));
                        }
                        break;
                    
                    case 'boolean':
                        $fields[] = $column . ' = ' . ($value ? '1' : '0');
                        break;
                    
                    case 'integer':
                    case 'double':
                    case 'string':
                        $fields[] = $column . ' = ' . $this->fn_quote($key, $value);
                        break;
                }
            }
        }
        
        return $this->exec('UPDATE "' . $table . '" SET ' . implode(', ', $fields) . $this->where_clause($where));
    }
    
    public function delete($table, $where)
    {
        return $this->exec('DELETE FROM "' . $table . '"' . $this->where_clause($where));
    }
    
    public function replace($table, $columns, $search = null, $replace = null, $where = null)
    {
        if (is_array($columns))
        {
            $replace_query = array();
            
            foreach ($columns as $column => $replacements)
            {
                foreach ($replacements as $replace_search => $replace_replacement)
                {
                    $replace_query[] = $column . ' = REPLACE(' . $this->column_quote($column) . ', ' . $this->quote($replace_search) . ', ' . $this->quote($replace_replacement) . ')';
                }
            }
            
            $replace_query = implode(', ', $replace_query);
            $where         = $search;
        }
        else
        {
            if (is_array($search))
            {
                $replace_query = array();
                
                foreach ($search as $replace_search => $replace_replacement)
                {
                    $replace_query[] = $columns . ' = REPLACE(' . $this->column_quote($columns) . ', ' . $this->quote($replace_search) . ', ' . $this->quote($replace_replacement) . ')';
                }
                
                $replace_query = implode(', ', $replace_query);
                $where         = $replace;
            }
            else
            {
                $replace_query = $columns . ' = REPLACE(' . $this->column_quote($columns) . ', ' . $this->quote($search) . ', ' . $this->quote($replace) . ')';
            }
        }
        
        return $this->exec('UPDATE "' . $table . '" SET ' . $replace_query . $this->where_clause($where));
    }
    
    public function get($table, $columns, $where = null)
    {
        if (!isset($where))
        {
            $where = array();
        }
        
        $where['LIMIT'] = 1;
        
        $data = $this->select($table, $columns, $where);
        
        return isset($data[0]) ? $data[0] : false;
    }
    
    public function has($table, $join, $where = null)
    {
        $column = null;
        
        return $this->query('SELECT EXISTS(' . $this->select_context($table, $join, $column, $where, 1) . ')')->fetchColumn() === '1';
    }
    
    public function count($table, $join = null, $column = null, $where = null)
    {
        return 0 + ($this->query($this->select_context($table, $join, $column, $where, 'COUNT'))->fetchColumn());
    }
    
    public function max($table, $join, $column = null, $where = null)
    {
        $max = $this->query($this->select_context($table, $join, $column, $where, 'MAX'))->fetchColumn();
        
        return is_numeric($max) ? $max + 0 : $max;
    }
    
    public function min($table, $join, $column = null, $where = null)
    {
        $min = $this->query($this->select_context($table, $join, $column, $where, 'MIN'))->fetchColumn();
        
        return is_numeric($min) ? $min + 0 : $min;
    }
    
    public function avg($table, $join, $column = null, $where = null)
    {
        return 0 + ($this->query($this->select_context($table, $join, $column, $where, 'AVG'))->fetchColumn());
    }
    
    public function sum($table, $join, $column = null, $where = null)
    {
        return 0 + ($this->query($this->select_context($table, $join, $column, $where, 'SUM'))->fetchColumn());
    }
    
    public function error()
    {
        return $this->pdo->errorInfo();
    }
    
    public function last_query()
    {
        return $this->queryString;
    }
    
    public function info()
    {
        $output = array(
            'server' => 'SERVER_INFO',
            'driver' => 'DRIVER_NAME',
            'client' => 'CLIENT_VERSION',
            'version' => 'SERVER_VERSION',
            'connection' => 'CONNECTION_STATUS'
        );
        
        foreach ($output as $key => $value)
        {
            $output[$key] = $this->pdo->getAttribute(constant('PDO::ATTR_' . $value));
        }
        
        return $output;
    }
}
?>